1. Field of the Disclosure
This disclosure relates to a grill cooking surface having multiple independently controlled cooking zones.
2. Discussion of the Related Art
Conventional griddle plates or platens are made from steel or cast iron and are heated by tubular sheathed electrical heating elements as, for example, disclosed in U.S. Pat. No. 3,843,315. The heating elements are maintained in contact with the underside of the griddle plate by a clamping system to maximize heat transfer and prevent overheating of the heating elements. The clamping system involves a substantial and often complex metal fabrication that adds cost and weight to the cooking appliance. The clamping system is secured to the griddle plate by a large number of studs that are screwed into holes or welded on to the griddle plate. This also adds cost and weight to the cooking appliance.
A non-contact grill is described in U.S. Pat. No. 6,614,007 as having one or more separate heater boxes secured to the underside of the griddle plate. Separate infrared heating elements are disposed in the heating boxes so as to be separated by a gap from the underside of the griddle plate. This arrangement provides a substantially uniform heating to the underside of the griddle plate.
U.S. Pat. Nos. 7,082,941 and 7,575,000, both of which are incorporated herein in their entirety by reference thereto, disclose a conventional clamshell grill having a platen with a plurality of heating zones, spaced side to side. “Side to side” in this context means from the operator's left to right or vice versa, when they are standing in front of the apparatus facing the cooking surface. Each heating zone has a heating unit. Thermal transfer between adjacent heat zones is limited by air gaps and insulation. The heater unit of each zone has a heater that is disposed to attain substantially uniform temperature of the platen for that zone before a temperature sensor senses a set temperature during either pre-heat or recovery modes.
As such, conventional gas heated grill platen heating systems, as discussed above, have sectioned heating across the grill platen in side-to-side zones that are controlled by a single temperature control point for each heating zone front to back. (“Front to back”, as discussed in greater detail below, refers to the side of the cooking surface closest and furthest away from the operator, respectively, when they are standing in front of the apparatus facing the cooking surface.) Depending on the location and quantity of food product being cooked in each zone, sections of the grill plate can become over or under heated causing inconsistent product cooking times or doneness. In addition, in the grills described above, with one heater per zone, unnecessary and excess energy is consumed when each platen is only partially loaded with food product, and the entire zone is heated when only a portion of the grill surface is being used.
The present disclosure solves this problem by splitting up the front to back of each cooking platen into multiple independently controlled zones front to back, thus increasing grill plate temperature evenness during idle, partial and full load cooking operations. This becomes even more important when the grill has an upper clamshell cooking surface that does not cover the entire lower grill plate surface front to back. Conventional gas burner systems do not allow for the splitting up from front to back of each cooking platen into multiple independently controlled zones.
The present disclosure also provides many additional advantages, which shall become apparent as described below.